for the metadata, LLMs may not prove so great. Use MusicBrainz Picard or Beets
I run dozens of proxmox LXCs, most with docker, but can confirm that while proxmox is fantastic to host NFS shares, it is near impossible to mount external ones to LXCs without doing some weirdness on the host. best practice would be to turn the NFS into samba or something and configure the docker vms and LXCs to use that (45drives has awesome repos on GitHub that work really well; that’s how I worked around that issue) the only downside is you need to usually offload everything as a backup first before the switch.
I like to store useful medical and survival information either in my ArchiveBox and/or kiwix containers. I’ve also been meaning to put together a local wiki.js with more custom info. TubeArchivist is really good too for storing instructional videos for offline use, or videos I find incredibly useful that have a strong likelihood of being taken down by YouTube so I save them first.